MakerBot Pro 3D Printing Design Series: The Drone

MakerBot have created a 3D printing design study, which has been developed with the MakerBot Design Engineering Team.

MakerBot Pro Series: The Drone

Reverse engineering is one of the best ways to learn how a product works, while also sharpening other design and engineering skills in the process. Learn how MakerBot industrial designer Felipe Castañeda reverse engineered a drone and made iterative design improvements using 3D printing.

This study explores iterative design and the relationship between designers and their tools.

1. Dismantle and Evaluate Hardware Components.

You’ve probably taken something apart just to see how it works. Maybe you fixed it, maybe you marvelled at the ingenuity of the design, but something about it was fascinating.

Felipe Castañeda had this experience recently with a micro drone. It flies surprisingly well, has a camera, and even some stabilization features. With his curiosity getting the better of him, he decided to take it apart and reverse engineer it to create his own 3D printed design.

Using the existing motors, battery, and electronic boards, here’s how he did it: he began by disassembling the original drone carefully to expose the individual components and learn how they interact within the existing assembly design. Included in the assembly are a main board, a battery, an image board for the camera, and 4 motors for each of the four rotors.

Next, he considered what the constraints are going to be in his redesign; there’s a fixed distance between the motors, and the weight of his new design needs to be close to that of the existing design. Felipe planned to maybe alter the location of the ports, the positioning of the boards, the wire routing, the overall structure, and further optimize for durability.

2. Create Blind Solids Based on Components

Using the basic information Felipe had in front of him, he took measurements to design blind solids in CAD as placeholders for what the fixed constraints would be for a new, updated design. Calipers are a must for this. Try to get your dimensions down to at least 100 micrometers—especially at this scale.

3. Sketch New Design Variations, then Input to CAD

With the existing components represented in CAD, Felipe began sketching new variations of the crash resistant design. Putting the blind solids in CAD helped to explore possibilities with an even better understanding of the spatial relationships. Among other design decisions, he chose to change the arm structure to improve cable routing and add durability, while creating a more blocky, “kid friendly” hull.

4. Isolate New Components and Iterate Individually

Body: Working with a clamshell assembly, Felipe took a shotgun approach and committed to testing five different fixture schemes. Using a 3D printer was a huge advantage here; these small bodies print incredibly fast on the Replicator+. It’s also important to keep the limitations of the printer in mind; which are particularly complex, tiny features.

Arms: The main challenge here was cable routing. He tested a piping system for a cleaner look, however, it added too much additional weight to be feasible. Additionally, he tested trusses, which gave good strength and simplified cable routing.

5. Print Preparation and 3D Printing Constraints

With a finished design mocked up in CAD, Felipe imported the entire assembly into MakerBot Print to fine tune print settings. Mass economy is important, so he dropped the number of shells to 1, and the infill percentage to 3%. It took him a couple of tests to get down the perfect combination of shells and infill in order to keep the body light and the arms rigid enough to hold up the motor’s lift.

To ensure clean embossing on the low-relief logo on the top surface, he kept his text size larger than 8pt to avoid any spurring.

6. Print, Test – Repeat

With the prints finished, Felipe labelled everything before taking them off the build plate to begin assembly and weighing. This is the stage where he learned the most; some parts didn’t fit perfectly; some arms were too heavy; some component layouts that made sense on the screen were obvious failures in the real world.

Felipe took this batch of learnings and went back to iterating the individual components.

7. Fly the Printed Drone

Reverse engineering something is one of the best ways to learn how it works, while also sharpening other design and engineering skills in the process. You learn about the intentionality of design and manufacturing decisions and get to play a bit of forensics with why and how things are laid out the way they are. In this case, it was about hunting for opportunities for improvement, and the incremental improvements that define the iterative design process.